This invention relates to air control valves and valve assemblies for controlling air flow through a passage. An exemplary application is as a throttle or air control valve in an engine induction system.
It is known in the art to provide air valves, such as intake throttle valves and port deactivation valves for use in internal combustion engines. Such valves may be located in a valve body, a manifold runner connected to an engine intake port or another tubular air passage defining body. The valve may be formed as a flat plate secured against a flattened portion of a valve shaft and held in place by lock screws.
Assembly of the valve in the valve body may be accomplished, without making a jointed valve body. The shaft is first inserted into the valve body through bearings provided along the valve axis. The valve plate is then installed through an open end of the air passage and secured to the shaft in place by tightening the lock screws through the open passage end. The assembly process is simple but labor intensive and may be difficult in some applications, such as in port deactivation valves where the location of the valves in the manifold runners may make the assembly point difficult to reach. While alternative valve arrangements have been proposed, the valve structure and assembly method described above have been applied to metal throttle valves for engines over many years.
The present invention provides an alternative engine air control valve and assembly method for use in various applications. It is particularly suited for an air control valve in a plastic throttle body or intake manifold body. The valve shaft and valve plate are made from composite polymeric plastics that are formed to be welded together by localized melting and hardening processes such as by infrared laser welding.
In a preferred embodiment, the valve shaft includes an intermediate portion with a longitudinal open groove along one side. The valve plate is formed with central raised portion that engages the valve shaft in assembly. A tongue extends inward from the raised portion of the plate and is fitted into the shaft groove after assembly of the shaft into a valve body. The tongue is softened by a laser beam applied to the tongue/groove interface, welding the valve components together in the installed location.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.